What does a real call return?
For 6 positions at search depth 8, 67% of the played moves matched Stockfish's first choice, with an average loss of 3.3 centipawns and the verdict zone_grise.
Recorded on 2 November 2026 through the public MCP endpoint, service release 0.17.1. Inputs and full responses, response SHA-256 09e573a8a3e6…. Verdict values are the literal values the tool returns. Run the same inputs yourself to compare; elapsed times vary, and a new release may change the figures.
Checked against
- Legal SAN/UCI conversion and forced cleanup of an unresponsive engine; optional actual Stockfish analysis.
Recorded on release 0.16.1. These checks cover the listed cases, not every input. Evidence cards.
How it works
For each legal supplied position, the engine queries Stockfish through UCI and compares the played move with its best choice at a bounded search depth. Centipawn differences and match rates are descriptive indicators.
Inputs and units
Provide positions as FEN plus a played move in SAN or UCI notation, and a supported search depth. The web form includes a small reproducible example.
What the result contains
Per-move comparisons, average loss and an aggregate profile can support discussion of a game without identifying or accusing a player.
Connect and inspect the inputs
Initialize an MCP connection, call tools/list and inspect the schema for analyze_chess_game. The live lab provides a complete example with editable inputs.
Call this engine in one command
Node.js 20+ and npm. This downloads a small remote MCP client; it does not install the engine locally.
npx --yes --package https://scorecompute.com/downloads/scorecompute-call-0.14.2.tgz scorecompute-call analyze_chess_game --arguments '{"positions":[{"fen":"rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1","played":"e4"},{"fen":"rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1","played":"e5"},{"fen":"rnbqkbnr/pppp1ppp/8/4p3/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2","played":"Nf3"},{"fen":"rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2","played":"Nc6"},{"fen":"r1bqkbnr/pppp1ppp/2n5/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R w KQkq - 2 3","played":"Bb5"},{"fen":"r1bqkbnr/pppp1ppp/2n5/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R b KQkq - 3 3","played":"a6"}],"depth":8}'Client download, PowerShell input and verification →
Cite this engine
Engine identified by source hash, source SHA-256 4060ca4799be…. Evidence recorded on release 0.16.1; the public service currently runs 0.17.1. Replace the access date when you cite it.
ScoreCompute. Chess move comparison with Stockfish (analyze_chess_game), identified by source hash, source SHA-256 4060ca4799be4b61040a5131144c1b8ca3368bd5f430fbaf486a2e45a2222778. Evidence release 0.16.1, service release 0.17.1. https://scorecompute.com/engines/analyze-chess-game/ (accessed YYYY-MM-DD).
All engine citations · Evidence card
Execution and availability
ScoreCompute exposes this tool through MCP Streamable HTTP. Rust computation runs on a connected worker; the public website and MCP gateway run separately. Among these 22 scientific tools, CUDA is implemented for simulate_pi; the other scientific engines run on CPU. The separate contributor network runs two compiled public workloads: a π estimate and fixed synthetic schedule probes. Requests are bounded and concurrent work may be refused when capacity is occupied.
Record inputs, assumptions and returned provenance when sharing a result. The public observatory displays software client names and tool activity, without publishing calculation arguments or results.